Live Migration of a Logical Partition

Abstract

A partition migration mechanism migrates a logical partition executing an operating system and resumes the logical partition before all resources in the logical partition have been migrated. When a partition is being migrated, a call checkpoint mechanism creates checkpoints of the state of the operating system when the partition manager is called. Before performing the call to the partition manager, a check is made to determine if all resources required by the call are available. If so, the partition manager call is executed. If all resources required by the call are not available, a resource fault is indicated, which causes the operating system state from the last checkpoint to be restored and a corresponding virtual CPU to be preempted until the resource that caused the fault becomes available. Exceptions that do not require the missing resource may be performed while the virtual CPU awaits the resource to become available.

Description

BACKGROUND[0001]1. Technical Field[0002]This disclosure generally relates to data processing, and more specifically relates to the moving of a logical partition.[0003]2. Background Art[0004]Since the dawn of the computer age, computer systems have evolved into extremely sophisticated devices that may be found in many different settings. Computer systems typically include a combination of hardware (e.g., semiconductors, circuit boards, etc.) and software (e.g., computer programs). As advances in semiconductor processing and computer architecture push the performance of the computer hardware higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.[0005]The combination of hardware and software on a particular computer system defines a computing environment. Different hardware platforms and different operating systems thus provide differ...

AI Technical Summary

Benefits of technology

[0008]A partition migration mechanism moves a logical partition that is executing an operating system and resumes the logical partition before all of the resources in the logical partition have been migrated. When a partition is being migrated, a call checkpoint mechanism creates checkpoints of the state of the operating system when the partition manager is called. Before performing the call to the partition manager, a check is made to determine if all resources required by the call are available. If so, the partition manager call is executed. If all resources required by the call are not available, a resource fault is indicated, which causes the operating system state from the last checkpoint to be restored and a corresponding virtual CPU to be preempted until the resource that caused the fault becomes available. Exceptions that do not require the resource that caused the fault may be performed while the virtual CPU awaits the resource to become available. The result is a system that can very quickly migrate a logical partition with a minimum of downtime.

Problems solved by technology

If all resources required by the call are not available, a resource fault is indicated, which causes the operating system state from the last checkpoint to be restored and a corresponding virtual CPU to be preempted until the resource that caused the fault becomes available.

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